Planet Aura

I'm a newbie - let's get that out of the way. I'm running Carrara 8.1 Pro on an iMac OSX Lion. I animated a simple 7 second scene of the camera slowly panning around earth while it rotates. It will be part of a ship flyby.

I created a blue aura that looked the way I wanted in the render preview. Doing the final render, I get a thick over saturated glow around the outer part of the planet that looks nothing like my preview. I messed with it for an hour last night but couldn't figure it out. Any ideas? Even better - is there a good tutorial for planet glow?

Also, the final render showed the planet rotating but the aura also rotated away leaving the final few seconds with no glow. :(

Aura is a really bad post effect. I never use it because it always looks pixelated and granular, and it doesn't respect any scene scaling, just pixel width (I think).

If you have any of the plugins that give a fresnel (falloff) effect, you can make another sphere that glows blue (slightly large than your planet and cloud spheres) and set it's transparency with falloff so you can only see the edges. This will give your planet a "halo". Without falloff the transparency won't look very good...

Carrara's transparency shader has a fresnel setting as of C8..., but I am not familiar enough with it to offer settings suggestions...

The video uses three spheres. One for the planet surface, one for the cloud layer and one for the "atmosphere." For the atmosphere I used a medium blue shader in the color channel, a numerical slider in the alpha channel set to 1%, and a light blue color in the glow channel. I'll include a screen shots of the shader and the editor for the aura as I'm getting tired of typing.

Here's the caveats: I wouldn't use the noise functions in the editor and since it's a post effect other post effects won't play nice with it sometimes. It also won't respect lighting as you can see from the dark side of the planet. I just call it "atmospheric refraction." ;-)

For the animation, I rendered the background layer and the planet separately and composited them in post. Mostly to save render time.

Although aura may not be the best solution for the issue at hand I would not dismiss it as useless. Certainly it has provided just the right touch to images for me in the past. It can certainly be fiddly to tweak, though to a great extent that depends on how you are trying to use it.

I don't know if my example here shows how nice it can look (the image was rendered for print as a poster and looks much better that way), but it certainly makes extensive usef of Aura...

I Agree with Evil producer and Thoromyr, the glow shouldn't be dismissed . but I'm also thinking that if Holly and Fenric are suggesting not to use it ,..then there may be some differences with how this effect is working on the different platforms,. and it may be worth posting a couple of Pics,. so we can see if it's something that's visibly different on PC and Mac.

My main issue with using the aura in this instance is the fact that it uses Glow in the shader, to power the effect, and it produces an all round light effect.
The Sunlight should cancel out the effect on the part of the planet facing the light.

Also Note:
in the scene I posted above,.. I've left a (hidden) plane (vertex grid) which I had set up with a point at (camera) modifier, and it has a radial gradient shader applied to it, to create the same type of fake aura as you see in Mark Bremmer's tutorial, but using shaders instead of image maps,. this is ok-ish,.. but the effect is all round the planet. ...so I just made it invisible.

I was trying to get something useable without a plugin... Carrara's built in fresnel works to make the center of the refractive object show it's effect. For a good atmosphere glow you'd want the edges to show more effect....

I tried using some other shader tricks: light scattering, translucency.... Some things might work in certain circumstances, but Glow and a fresnel filter is easiest.

If you are feeling confidant you could use a SPLAT painted with a glowing ring. Parent the SPLAT to your Earth/Clouds group, and make the group point at the camera. Totally fake, but totally controllable...

so we can see if it's something that's visibly different on PC and Mac.

I could post some, but all you'd find is that they are identical. I'm almost 100% OS X now (still run Carrara in Wine on linux occasionally), but I've done a fair amount of crossplatform rendering. There may be some area where they do differ, but I've never encountered it.

My main issue with using the aura in this instance is the fact that it uses Glow in the shader, to power the effect, and it produces an all round light effect.

I was trying to get something useable without a plugin... Carrara's built in fresnel works to make the center of the refractive object show it's effect. For a good atmosphere glow you'd want the edges to show more effect....

I was trying to get something useable without a plugin... Carrara's built in fresnel works to make the center of the refractive object show it's effect. For a good atmosphere glow you'd want the edges to show more effect....

Did you try subtracting the fresnel from a value?
I'm not sure that would be possible because of where the fresnel control is located. It is not in the "tree" so I am not sure how that could work....